My New Hyundai Accent ICE

This is a discussion on My New Hyundai Accent ICE within In-Car Entertainment, part of the Under the Hood category; Sorry i forgot to mention that after few days the alternator whine is back again. Let me mention what all ...

Sorry i forgot to mention that after few days the alternator whine is back again. Let me mention what all steps we have already tried:
1. Changed the route of RCA and power cable, they are not going together anymore.
2. Changed the RCA Cables with branded ones.
3. Grounded the HU with Copper on RCA outs.
4. Already Isolated the AMP not being the point of failure by checking the AMP in a different car.

Redo the amp ground. Make sure the area where the washer / wire makes contact is scraped clean till the base metal shows. Alternately, if you can, get a copper / brass washer brazed at the place to improve the contact with the ground wire.

Thanks for the suggestions guys.
@panky: Like i mentioned i have already isolated that the amp is the not the problem. Pio techniques are already in place.
I will try to sand the screw for amp grounding.
Please give your inputs on the phase 2 upgrade as well.

Hi Guys,
Finally the alternator whine is gone, I changed the painted screw with a new screw (non painted) and the noise was gone for some time, when i drove the car for few KMs the noise came back agian.
I had a noise filter lying there in my car, so i tried it and IT WORKED.
The issue has been resolved successfully.
@Panky : I tried the tuning part yesterday. What i did is Moved all the HU settings to flat. Turned off the rear speakers and Tuned the front speakers then i did the same for the Rear speakers.
RESULTS: Now i have only Treble and Mid Range from the front speakers and The bass is coming from the Rear speakers.